This invention relates to apparatus for fabricating printed circuit boards, and more particularly to apparatus for inserting terminals into printed circuit board apertures.
One of the steps frequently required in fabricating printed circuit boards ("PCBs") is the insertion of relatively small metal terminal sockets or pins through an aperture in the board. This is often done by means of automatic or semi-automatic terminal inserting machines which hold the PCB at or near its peripheral edges, strip a terminal from a belt or tape containing a succession of terminals, and drive the terminal down through an aperture in the PCB. After each terminal is applied, the machine automatically or semi-automatically indexes the PCB relative to the terminal inserting fixture so that the next PCB aperture requiring a terminal is under the inserting fixture.
Because the terminal inserting machine typically holds and therefore supports the PCB only at its peripheral edges, additional temporary PCB support is usually required at the location at which a terminal is being inserted in order to prevent undue deflection of the PCB as the terminal is inserted. This temporary support has been provided by an anvil assembly which moves up underneath the PCB as the inserting fixture is moving down. However, the known anvil assemblies have several important deficiencies. Among these deficiencies are (1) relatively large anvil size which prevents insertion of closely spaced terminals, (2) anvil surfaces which can damage delicate printed circuitry on the side of the PCB in contact with the anvil, and (3) relatively crude and short-lived structures for detecting the successful insertion of a terminal by electrical continuity through the inserting fixture, the terminal, and the anvil.
In view of the foregoing, it is an object of this invention to improve anvil structures for use in PCB terminal inserting machines.